A woman protesting the shooting death of Alton Sterling is detained by law enforcement near the headquarters of the Baton Rouge Police Department in Baton Rouge, Louisiana, on Saturday.

Jonathan Bachman/Reuters

Hundreds spent the night behind bars on Saturday after thousands of demonstrators took to the streets of major U.S. cities to protest the killings of Philando Castile in a suburb of St. Paul, Minnesota, and Alton Sterling in Baton Rouge, Louisiana.* More than 200 people were arrested in Baton Rouge and St. Paul alone, including prominent Black Lives Matter activist DeRay Mckesson, who broadcast his own arrest live on Periscope.

Mckesson, a Baltimore resident who has emerged as one of the most visible voices of the Black Lives Matter movement, was arrested at around 11:15 p.m. after police warned protesters in Baton Rouge not to go into the road. McKesson repeatedly notes in his Periscope video that there was no sidewalk. “They are literally just provoking people,” McKesson says in the video in which he repeatedly complains about how police had been provoking protesters. The video then gets shaky: “City police. You’re under arrest. Don’t fight me. Don’t fight me.” And then Mckesson shouts: “I’m under arrest, y’al!” Somebody then grabs the camera and other protesters demand answers from the police.

McKesson sent a text message to the Washington Postsaying he was arrested with almost three dozen other activists. Police confirmed the arrest but didn’t clarify any potential charges against the activist turned Baltimore mayoral candidate. “As of 5:15 this morning he was physically OK, we are still awaiting his release,” Brittany Packnett, a fellow activist told the New York Times over the phone. “Potentially his charges are for obstructing traffic even though everything proves he was behind the white line and was tackled by police behind the white line.”

Local public radio station WWNO wrote on Twitter that one of its reporters was also arrested in Baton Rouge “on one count of obstruction of highway.”

.@WWNO reporter remains in police custody on one count of obstruction of highway.

The police in Baton Rouge “grew more aggressive” as the night went on and “at least twice, officers outfitted in riot gear charged at a group of protesters,” reports the Advocate. A spokesman for the Louisiana State Police said protesters were lying when they said police were arresting people who weren’t on the road. “They were clearly blocking the roadway—we respond to their actions,” he said. “We are only arresting those that are violating the law by stepping into the roadway.”

Police rush the crowd of protesters and start making arrests on Saturday in Baton Rouge, Louisiana.

Mark Wallheiser/Getty Images

In the St. Paul demonstration that began at the governor’s mansion, some 100 protesters were arrested. Around 50 of the arrests took place when demonstrators blocked a freeway and the rest took place at a follow-up protest in St. Paul. Protesters said police officers fired tear gas and rubber bullets at protesters. Around 21 police officers were injured from demonstrators “throwing rocks, bottles, fireworks, and bricks,” a police spokesman said. One officer was allegedly hit in the head with a large piece of concrete. “This is the first time in my 28 years we have observed this level of violence toward our public servants,” Police Chief Todd Axtell said. “It’s really a disgrace.”

Protestors shut down highway I-94 on Saturday in St. Paul, Minnesota.

Stephen Maturen/Getty Images

There were also protests in other major cities, including Atlanta, Miami, New York, Nashville, and Washington, D.C., among others.